Zika virus infection: guidance for primary care

As of February 2019, Public Health England (PHE) has withdrawn Zika virus infection: guidance for primary care. The algorithm for the assessment of pregnant women with a history of travel during pregnancy to areas with active Zika virus (ZIKV) transmission has not been withdrawn but has been updated. The Guidelines team is in the process of reviewing this summary.

You can find a collection of the most up-to-date PHE guidance on ZIKV on the PHE website.

General travel advice for patients

Those working in primary care may be consulted by patients travelling to or returning from areas with active Zika virus transmission. Pregnant women may also request letters to justify suspension of travel to affected areas on medical grounds. In such cases, those working in primary care can refer to updated National Travel Health Network and Centre (NaTHNaC) advice

It is recommended that pregnant women planning to travel should postpone non-essential travel to areas with active Zika virus transmission until after pregnancy. In addition it is recommended that women should avoid becoming pregnant while travelling in an area with active Zika virus transmission, and for 8 weeks after their return. In the event that travel to an area with active Zika virus transmission cannot be postponed, the pregnant traveller or those planning pregnancy must be informed by the healthcare provider of the risks which Zika virus infection may present

In addition, the use of scrupulous mosquito bite avoidance measures both during daytime and night time hours (but especially during mid-morning and late afternoon to dusk, when the mosquito is most active) should be emphasised, and an information leaflet provided

All pregnant women who have recently travelled to a country where active Zika virus transmission is reported should notify their primary care clinician, obstetrician or midwife

All travellers to areas with active Zika virus transmission should practise mosquito bite avoidance measures, both during daytime and night time hours (but especially during mid-morning and late afternoon to dusk, when the mosquito that transmits Zika virus is most active)

An application of insect repellent containing 50% DEET (N,N-diethyl-m-toluamide) will repel mosquitoes for approximately 10 hours if used as per instructions. Repellents containing up to 50% DEET can be used by pregnant women, but higher concentrations should not be used. When both sunscreen and DEET are required, DEET should be applied after the sunscreen. Sunscreen with a 30 to 50 SPF rating should be applied to compensate for DEET-induced reduction in SPF. The use of DEET is not recommended for infants less than two months of age

Revised algorithm* for assessing pregnant women with a history of travel during pregnancy to areas with active Zika virus (ZIKV) transmission †

*This guidance will be updated as more information becomes available. Currently this algorithm applies to women at all stages of pregnancy although infection in early pregnancy is likely to be the greatest risk†Laboratory testing is performed by the PHE Rare and Imported Pathogens Laboratory (RIPL). Given the overlap of symptoms and endemic areas with other viral and bacterial infections, RIPL will routinely test significantly symptomatic pregnant women (those hospitalised and/or acutely unwell) returning from areas with active ZIKV transmission for dengue, chikungunya and other infections as well as ZIKV‡Assessment of pregnant women should be based on a history of travel to countries and territories reporting active ZIKV transmission in the last 9 months. This is in contrast to pre-travel advice where countries or overseas territories are classified as having current active ZIKV transmission if confirmed autochthonous cases have been reported in the last 3 months§Clinical illness is suggestive of Zika virus disease if a combination of the following symptoms are reported: rash; itching/pruritis; fever; headache; arthralgia/arthritis; myalgia; conjunctivitis; lower back pain; retro-orbital pain|A pregnant woman with typical Zika virus symptoms (as above) that began within 2 weeks of sexual contact with a male sexual partner who has recently travelled (within the previous 8 weeks) to an area with active ZIKV transmission, should be tested regardless of her own travel history, due the possibility of sexual transmission¶Appropriate samples are a clotted blood (or serum) and, if indicated, an EDTA blood (or plasma) and/or a small volume of urine without preservative. The samples must be submitted with a single RIPL request form. This form must clearly state the pregnancy gestation and both the travel history (i.e. which countries visited and the dates of the outward and return journeys) and the clinical details (ie the patient’s symptoms and the date of illness onset). This is so that the appropriate investigations can be performed and their results correctly interpreted. ZIKV testing will be performed using real-time PCR and serology. For more information refer to: Zika virus: sample testing advice **In order for negative Zika virus serology results to exclude previous Zika virus infection, this should be a serum sample collected 4 weeks or more after the last possible Zika virus travel-associated or sexual exposure††This evaluation and follow-up is likely to include repeat fetal ultrasound and blood testing for ZIKV RNA at four weekly intervals, and consideration of fetal MRI. Abnormal fetal findings will prompt appropriate investigation including, for example, submission of booking and current serum samples for toxoplasma, rubella, parvovirus and CMV serology. Amniocentesis may be considered for ZIKV PCR‡‡For women who have not had symptoms, taking and storing a clotted serum sample locally, without immediate testing, is recommended. In the event that there is a later concern about fetal development, this sample will be available for retrospective testing, including detection of Zika virus antibodies. For more information refer to: Zika virus: sample testing advice§§This is in line with WHO guidance on the management of asymptomatic pregnant women who have returned form Zika-affected countries||In this context, ‘small fetal head’ is defined as: head circumference more than two standard deviations below the mean for gestational age, i.e. below the 2.5th centile¶¶Apart from microcephaly and intracranial calcifications, other brain abnormalities that have been reported in association with ZIKV infection are ventriculomegaly, cell migration abnormalities (e.g. lissencephaly, pachygyria), and arthyrogryposis (congenital contractures) secondary to central or peripheral nervous system involvement

Preventing potential sexual transmission of Zika virus

The risk of sexual transmission of Zika virus is thought to be low, relatively few cases of male-to-female transmission have been reported, almost all involving men who experienced symptoms of Zika virus infection. Transmission from an asymptomatic male who had travelled to an area with active Zika virus transmission has been reported. Transmission of Zika virus from a female to a male sexual partner, and from a male to a male sexual partner has also been reported, but these appear to be very rare events

If a female partner is at risk of getting pregnant, or is planning pregnancy, effective contraception is advised to prevent pregnancy AND condom use is advised during vaginal, anal and oral sex for a male traveller to reduce the risk of transmission during travel and for:

8 weeks after his return from an area with active Zika virus transmission if he has not had any symptoms compatible with Zika virus infection

six months following recovery if a clinical illness compatible with Zika virus infection or laboratory-confirmed Zika virus infection was reported

the remaining duration of pregnancy if he is the partner of a pregnant woman, regardless of a history of symptoms suggestive of Zika virus infection

Recommendations for women planning pregnancy who have travelled to or arrived from an area with active Zika virus transmission

After a woman leaves an area with active Zika virus transmission, it is recommended that she should avoid becoming pregnant for 8 weeks

Recommendations for pregnant women who have travelled to or arrived from an area with active Zika virus transmission

There is scientific consensus that Zika virus is a cause of microcephaly and other congenital anomalies, but detailed knowledge about Zika virus infection and pregnancy is limited and continues to evolve. Recommendations are based on current information and are likely to be updated periodically to reflect emerging evidence

A pregnant woman with a history of travel during pregnancy to an area with active Zika virus transmission who reports current or previous clinical illness that raises suspicion of Zika virus disease, should be tested for Zika virus infection, and have a baseline fetal ultrasound via referral to a local antenatal ultrasound service

Symptoms and signs of clinical illness in a pregnant woman include the following:

rash

itching/pruritus

fever

headache

arthralgia/arthritis

myalgia

conjunctivitis

lower back pain

retro-orbital pain

Clinicians should consider other:

travel-associated infections including dengue and chikungunya virus infections, malaria, common infections and non-infectious diseases in the differential diagnosis

causes of rash in pregnancy in the differential diagnosis, as appropriate (further guidance is available from PHE)

All other pregnant women who have travelled to an area with active Zika virus transmission during pregnancy but who have not reported clinical illness should be offered a baseline ultrasound scan; consideration of storing a serum sample locally is also advised (refer to the full guideline for further information)

For further information, refer to the algorithm above and the full guideline

Recommendations for all other (non-pregnant) patients who have travelled to or arrived from an area with active Zika virus transmission

Symptomatic Zika virus infection is typically a mild and self-limiting illness. Clinicians should also consider other travel-associated infections including dengue and chikungunya virus infections, malaria, common infections and non-infectious diseases in the differential diagnosis

Symptoms and signs of clinical illness include the following:

rash

itching/pruritus

fever

headache

arthralgia/arthritis

myalgia

conjunctivitis

lower back pain

retro-orbital pain

For non-pregnant individuals who report current or previous symptoms suggestive of Zika virus infection, refer to sample testing advice

Non-pregnant patients who do not have current symptoms

Non-pregnant patients who were diagnosed elsewhere and who have since recovered from their infection do not require further investigation and can be reassured that Zika virus infection is typically short-lived and self-resolving. For male travellers diagnosed elsewhere, refer to advice about preventing potential sexual transmission (see note above about further testing for male travellers with pregnant partners). If there are concerns about persistent symptoms beyond the expected recovery time for Zika virus infection, then discussion with a local infection specialist is recommended

Diagnostic laboratory testing

Diagnostic laboratory testing is available from PHE’s Rare and Imported Pathogens Laboratory (RIPL).The recommended sample types for testing will depend on whether the patient has current symptoms or previous symptoms that have now resolved

Further information

Please refer to the full guideline for information on:

immunocompromised patients

queries about donating blood, tissues or semen

minor procedures in the primary care setting

notifications and specialist advice

Additional resources

Additional information about Zika virus for health professionals is available on the PHE website